Adjustable internal gauge



J. BATH ADJUSTABLE INTERNAL GAUGE Filed Oct. 18 22 Omw mm Wm I nu L 3 w 91 w\ 2, M Q Wm Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE JOHN DATE, OF WORCESTER, MASSACHUSETTS.

ADJUSTABLE INTERNAL GAUGE.

Application filed October 18, 1922. Serial Ill'o. 585,428.

To all whom it may concern:

Be it known that I, JonN BATH a citizen of the United States, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented a new and useful Adjustable Internal Gauge, of which the following is a specification.

This invention relates to an adjustable gauge. designed for accurate measurement of internal diameters.

In the particular embodiment illustrated in the drawings, the gauge is arranged for the measurement of internal screw threads but certain features thereof are not limited to such use.

One object of my invention is to provide a construction in which more convenient and accessible provision is made for longitudinal adjustment to prevent lost motion between the parts.

A second object is to provide an improved device for taking up lost motion or back lash between the operating shaft and the threaded member on which the gauge bars are supported and by which they are radially adjusted.

Another feature of my invention relates to the provision of a threaded pilot for an internal gauge, by means of which the device when used as a thread gauge, may be more quickly and easily entered 1n the work.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A. preferred form of my invention is shown in the drawings, in which Fig. 1 is a plan view of my improved gauge;

Fig. 2 is a longitudinal sectional elevation thereof;

Fig. 3 is a transverse sectional elevation taken along the line 33 in Fig. 1, and

Fig. 4 is a detail longitudinal section of a slight modification.

Referrin to the drawings, I have shown an adjusta le internal gauge comprising a body "in which a shaft 11 is rotatably mounted. A member 12 is threaded on the shaft 11 and forms a sup-port for a plurality of gau e bars 13. These bars 13 are preferably o dove-tailed section, as shown in Fig. 3, and their inner bearing faces are also slightly inclined relatively to th axis of the gauge. The bars are a close sliding fit in the member 12 and are adjusted radially by movement of the member 12 axially.

The bars 13 are held from longitudinal movement by engagement at one end with a flange 14 on the end of the body 10 and at the other end with a disc or plate 15 mounted on the end of the shaft 11. The disc 15 is preferably provided with an inwardly extend' hub or boss 16 to receive the head 17 of e shaft 11. Keys 18 and 19 are fixed on the flange l4 and the plate 15 and are disposed in of the gauge bars 13, thus preventing angular movement of the bars 13 or plate 15 relative to the body 10.

The member 12 has a recess 20 which the. hub 16 of the plate .15 is relatively slidable and also has a projection 21 slidabie in a recess 22 in the end of the body 10. All portions of the screw thread on the shaft 11 are thus fully protected from dirt agd injury in all positions of the member 1.

When the device. is used as a thread gauge, the outer faces of the bars 13 are provided with screw threads 23 and the edge of the plate 15 is also threaded as indicated at 2%, the threads being of very slightly smaller dimensions than the thread to be measured. The plate 15 thus acts as a threaded pilot by which the gauge may be quickly and easily entered in the work.

I have found it desirable to provide recesses or grooves 15' in the threaded eriphery of the plate 15 so that any 0 ips or dirt in the thread to be measured may accumulate in these recesses instead of being crowded into the screw threads.

At its opposite end, the shaft 11 is provided with a sleeve 25 keyed and slidable thereon and engaging a steel washer or other bearing surface 26 at the end of the body 10. Lock nuts 27 on the end of the shaft 11 provide for accurate adjustment of the sleeve 25 on the shaft. These nuts are preferably separated by a washer 28 having a lug or projection extending into a key-way on the shaft and thus preventing relative angular movement of the washer. The nuts 27 may be provided with slots so that they may be conveniently adjusted by a spanner Wrench. 4

A tubular casing or cap 30 is slidable on the sleeve 25 and may be secured in position by a set screw 31. This casing encloses and radial slots in one cooperates with an index flange 33 on the body to give accurate indications of the diameter of the gen e. By loosening the set screw 31-and slig tly withdrawing the casing 30, thegraduated disc 32 may be set in any desired relative angular sition, which relative position will be e ectively maintained b restoring the casing to en agement t erewith.

Fig. 4 I have shown convenient means .fortaking up back lash between the threaded member 12 and the shaft 11. For this purpose the part 35 corresponding to the extension 21 previously described is provided with a sli htlv tapered screw thread upon which is tted an adjusting nut 36. By slightly tightening this nut any wear between the member 12 and the shaft 11 may be easily taken up.

Certain general features of my invention are not claimed herein, as they form the sub'ect matter of a co-pending application, Senal No. 300,053, filed May 27, 1919.

Having thus described myinvention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims but what I claim is 1. An adjustable internal gauge having, in combination, a 'supportvhaving an elongated axis a plurality of gauge bars movable radially in said sup ort and having -inner bearin surfaces inclined relatively to the axis of t e gauge, means engaging said inclined bearing surfaces and efiectlve to move said bars simultaneou 1y radially, said gauge bars havin screw threads thereon, and a threaded pi ot mounted ad'acent the outer ends of said gauge bars and eld from angular movement relative thereto.

2. An adjustable internal gauge having, in combination, a support having an elongated axis a pluralit of gauge bars movable radially in sai sup ort and having inner bearin surfaces inclined relatively to .radially in said su port an the axis of t e gauge, means enga in said inclined bearing surfaces and e ective to move said bars simultaneously radially, said gauge bars having screw threads thereon, and a plate mounted adjacent the outer ends of said bars and having a pilot thread formed on its edge with approximately the dimensions of the thread to be'measured.

3. An adjustable internal gauge having, in combination, a support having an elongated axis a plurality of gen e bars movable having inner bearing surfaces inc 'ned relatively to the axis ber ma axis a of the gauge, means en aging said inclined bearing surfaces and e ective to move said bars simultaneously radially, said uge bars having screw threads thereon, a p ate forming the end of the au e and holding said bars from longitud iiia displacement, and means to prevent relative angular movement between said plate and bars, said late having athread formed thereon and 0ming a pilot by which said gauge bars may be entered in the work.

4. An adjustable internal gauge having, inconibination, a support having an elongated axis a plurality of gau bars movable radially in said support and having inner bearin surfaces inc ined relatively to the axis 0 the gauge, means eng said inclined bearlng surfaces and e ective to move said bars simultaneously radially, said means including ,a threaded member in which said bars are relatively slidable, a threaded shaft on which said member is threaded, said member having a tapered threaded extension, and a nut fitting said tapered extension and b which said membe closely a justed to fit said threadge1 (slhaft.bl a1 h 5. 'a justa e intern ga aving' in combination, a body having an e l ii ted axis, a plurality of gen bars movab e radiall and having inner arin surfaces inclined relatively to the axis of t e gau means to move said bars simultaneousl; radially, said means including a threaded member in which said bars arerelatively slidable, a threaded shaft rotatable in said body and on which said member is threaded, and

means to prevent relative l 'tudinal movement of said shaft, gauge are and body, said means com ris' a sleeve keyed to said shaft and s idab e to a shoulder fixed relatively to said wind devices on the shaft to adjust said sleeve axially. d b1 6. n a 'usta e internal ha in combination, a body having a ii zlo idi plurality of gauge bars movabgradially and having inner surfaces inclined relatively to the axis of the gs means to move said bars simultaneo y radially, said means including a threaded member in which said bars are relatively slidable, a threaded shaft rotatable in said body and on which said member is threaded, and means to prevent relative lo 'tudinal movement of said shaft, gauge are and body, said means com ris' a sleeve keyed to said shaft and idabe to e a shoulder fixed relativel to said y, devices on the shaft to just said sleeve axially, and a removable case for said shaft, covering and protecting sai adjusting devices.

7. An adjustable internal gs ha combination, a body having 1 :10:13?! "9 axis, a plurality of gauge bars movable radially and having inner bearing surfaces inclined relatively to the axis ol the gauge, means to move said bars simultaneously radiall said means including a threaded mem er in which said bars are relatively slidable, a threaded shaft rotatable in said body and on which said member is threaded,

means to prevent relative longitudinal movement of said shaft, auge bars and body, a graduated disc, adjusting devices therefor, and a casing eflective to engage and lock said disc, said casing enclosing said adjusting devices and being removable to afl'ord access thereto,

8. ln an adjustable internal gauge, a

body, an actuating shalt therein, a sleeve ke ed to said shaft, lock nuts on the end of said shaft to hold said sleeve in fixed axial relation with said body, an index member on said body, a cooperating index collar loosely mounted on said sleeve, and a tubular locking member mounted on said sleeve and having a toothed end portion cooperating with a similar portion of said collar to hold said collar in adjusted angular position, said tubular member also enclosin said lock nuts and being removable to afi'ord access thereto.

In testimony whereof I have hereunto aed m si ature.

y gn JUHN BATH. 

